1. Field of the Invention
The present invention relates to a biopsy tissue sampling treatment instrument which is inserted into the body of a patient and used to take samples of tissue in the body.
2. Description of the Related Art
In recent years, treatment instruments for transbronchially taking samples of living tissue have been widely used, for example, to carry out pre-treatment diagnosis of cell abnormalities using a bronchoscope. Such treatment instruments are disclosed, for example, in Japanese Patent Application Laid-Open Publication No. 2001-29349, Japanese Utility Model Application Laid-Open Publication No. 7-33305, Japanese Patent Application Laid-Open Publication No. 9-192135, and Japanese Patent Application Laid-Open Publication No. 5-15543.
Regarding treatment instruments generally used with endoscopes, wide use is made of endoscopic needle biopsy forceps equipped with a pair of opening-closing forceps cups such as disclosed in Japanese Patent Application Laid-Open Publication No. 2001-29349. In the conventional endoscopic needle biopsy forceps, a needle is disposed so as to protrude in a pair of forceps cups, and a thorn-like portion which protrudes obliquely backward is provided near a distal end of the needle.
Japanese Utility Model Application Laid-Open Publication No. 7-33305 discloses an endoscopic bacteria sampling brush or a so-called cytological brush which takes a sample of mucosae from a lumen of a living body by scratching a luminal wall of the living body with a protruding brush unit and causing the mucosae to adhere to the brush unit. Furthermore, Japanese Patent Application Laid-Open Publication No. 9-192135 discloses a cytological brush which takes a sample of living tissue using multiple flaps provided in a distal part of an operation sheath different in form from the brush unit disclosed in Japanese Utility Model Application Laid-Open Publication No. 7-33305.
Besides, Japanese Patent Application Laid-Open Publication No. 5-15543 discloses a cell sampling tool which includes a body piercing member equipped with a piercing head rotationally disposed at a flexible distal end, where a spiral cell sampling groove is formed in a suitable shape in the piercing head.